Japan are competing in their 22nd World League and their best performances were sixth-place finishes in 2008, 1993 and 1990. Last time out they finished joint-bottom of Group 2 with Korea after winning just one of their Pool D matches, exiting the competition at the first stage. They failed to qualify for the 2014 World Championship, the first edition they have missed in 44 years. Coach Masashi Nambu was appointed in February 2014 with the dual mission of qualifying for the Rio de Janeiro 2016 Olympic Games, while also bringing on the young players who will be hoping to shine at Tokyo 2020. His team's 2014 season finished with the Asian Games, where they took the silver medal after losing to Iran in the final.

Japan joined the FIVB in 1951 and have long been one of the strongest sides on their continent, winning the Asian Championship seven times and the Asian Games eight times. They took part in the World Championship for the first time in 1960, heralding an era of success. They won a bronze medal at the Tokyo 1964 Olympic Games and silver at Mexico 1968 before taking gold at Munich 1972. But the subsequent decades have proved less fruitful and they missed three successive Olympic Games before returning to the stage at Beijing 2008 where they failed to win a match.

Masashi Nambu has been Japan's men's national team coach since February 2014. That year he led the team to a silver medal at the Asian Games and an equal-11th finish in Group 2 of the World League. Nambu has aimed to build a strong platform for Japan for future Olympic Games success while in his role as head coach. Nambu, who was born in Osaka, also coached the club side Matsushita Panasonic Panthers from 2002 to 2014. It was there that he won Japanese Head Coach of the Year honours three times and led his team to three domestic titles. As a player he earned Top Six honours at the 1997 and 1999 Kurowashiki All-Japan Tournaments.